Acrylic is a modern synthetic paint. It is fast-drying and combines some of the key properties of watercolor and oils. Acrylics are made with a resin that is derived from polymers of acrylic acid or acrylates. Most acrylic paints are water based, but become water resistant when dry.
In essence, acrylics are a refined version of paints developed for industrial use and can be applied to almost any surface with a variety of tools in order to create effects ranging from thin washes, smooth surfaces, to rich impasto with either a semi-gloss or matt finish.